- Thread starter
- #21
Seems like the transmission oil must have been hotter than the coolant as it blew from the bottom. Either way, shouldn't be blowing up. Must of not done a good job joining the plastic bottom tub to the core.
A little radiator blow out captured on Ring cam. FZJ80 plastic radiators.... (1 Viewer)
- Thread starter TexFJ
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
denso is oe but it may not necesarally be made in japan as denso id a global company and may be made elsewhere but it will still meet their qc.
since your replacing the rad is replace the hoses, t-stat and rad cap while your doing that
Denso - probably China or...... OEM is made in Japan by TRAD- this thread is not an accurate representation of the radiator itself as many original radiators have gone 20 years plus then were replaced as a precaution due to age and an OCD Mud maniac owner. Why did so much pressure build up in the system? This is what I’d be trying to determine.
Good luck with a CSF 2517 in an 80. You will read many posts from those whose engine it couldn’t keep up with especially if you live in a warmer part of the world. I bought one in 2016 and ran it a little over 2 years. It just couldn’t keep up when the going got tough. Temps would creep up and up. 100 degrees outside, AC on, 70 mph = 219f for miles and don’t even talk about a hill. I don’t care so much for plastic radiators myself but spending over a grand for a Ron Davis was out of the question and cheap aluminum units from the Far East, not a chance, so I gave in an ordered OEM online. In the 2 years since I installed the TRAD radiator I don’t think I’ve seen 200f on my Koso coolant temp gauge.
Many members down in AZ are fond of the TYC radiator that comes with a fortune cookie. It may or may not last 5 years but they say it cools the engine well in AZ heat.
Last edited:
Yup, I was a little more stubborn (hard headed) and ran my CSF for 5 yrs. Now, it's stored at home in case my TYC fails. The TYC is cheap - some, including myself, consider it a consumable, tolerating the plastic and fragile appearance. But no radiator that I've heard of - including the $1K Ron Davis, will out perform it in cooling performance. I can pull the CSF out, if there's some delay in getting another TYC. And something else to consider, @TexFJ , aluminum is more efficient than the copper/brass CSF or pre-1995 OEM. When Toyota went from the 3 row copper/brass OEM to the 2 row aluminum in 1995, with a cooling performance improvement, it makes sense to stay with aluminum or convert to aluminum, as I did with my '94. All metal has the edge for ruggedness and field fixability, but aluminum cools better. Some want both advantages and will spring for the Ron Davis. One thing's for sure, if your 80 is armored up (more weight) and running larger tires, and you're trying to run A/C because it's hot outside - 95+F, your engine temp is going to climb uncomfortably and can result in running in the red. Don't trust your OEM temp gauge, unless it has the RT mod so it gives you an accurate reading. You can also get an after market gauge or run a scan gauge if your 80 is OBD II ('95-'97).
I would also be concerned to find the reason pressure built up. Just replacing parts may not fix it, if you still have the pressure issue.
Fortune cookie....I love it
Just curious. Was the siphon tube on your overflow tank cap in place? Or had it fallen into the tank?
For reference: Check Ur Siphon: Potential Cooling Issue, Easy Fix - https://forum.ih8mud.com/threads/check-ur-siphon-potential-cooling-issue-easy-fix.1246645/
Was this radiator original?
- Thread starter
- #29
248K on the car. The radiator had about 50K since 2012.
- Thread starter
- #30
The reason for the pressure build up was stupid. I was actually trying to find a noise that appeared under load. Chocked the car with parking break on and had son rev it up in drive up to about 3,500 rpm. Didn't take long for the transmission oil to get scotching hot and obviously it showed up in the poor design of the radiator. The coolant was escaping into the overflow container but perhaps not fast enough. For it to blow, the cap must have not been doing its job good enough. pressure built up somewhere. I'm glad it happened at home vs. on the trail.
The bottom of the radiator seems to be just clamped on with the numerous tabs.
The bottom of the radiator seems to be just clamped on with the numerous tabs.
The design of the tank retention system allows the tank and tank seal to be repaired or replaced without needing someone with the tools and ability to braze properly. Revving the motor in park won’t super heat the fluid because the torque converter isn’t shearing fluid under a load. When was the last time the HG was replaced?
Last edited:
When I found my full overflow tank and finally figured out why, there was airspace in the top of the radiator from the top of the coils up, i.e. the whole top tank was nothing but air, even though the overflow tank gave the appearance of being, well, topped up. The tank didn't fail here, but I didn't try to quick cook it at 3500 rpm stalled either. Plenty of headspace to build up steam, though, and that wouldn't be a good thing when you want hot water instead.
So the engine wasn't idling when it blew? If so, I'm still wondering what the squeal noise was just before the explosion. And you said the water pump wasn't seized. It make sense now, that a tranny cooling line also blew apart. I'm wondering if it was tranny or torque converter complaining. Anyway, interesting video! I think I'd also flush and replace your tranny fluid before doing a trip of any length. You'll want to test it before flushing to be sure it wasn't damaged during your previous testing for the noise under load.
Ford enthusiasts have an interesting way of flushing tranny fluid that should work with our 80's. Take the return line from the radiator off at the tranny and have it drain into a bucket while some one is dumping new fluid into the tranny dipstick tube while the engine is running. When the fluid that's running out the line into the bucket is new fluid, ( you can tell by the color, usually) it's flushed. Shut off engine, button it up and top fluid off with normal fluid level check procedure. This method poses minimum chance of damaging tranny.
Last edited:
Wow.
3500 RPM in gear, brakes on, wheels chocked.........
Yes, SOMETHING was going to fail and it found the weakest link in the cooling system.
After something like that, you're going to need to look at transmission, U-Joints, Drive line....
I'm sorry, but that kind of RPM strain and holding it back is just stupid.
thatcabledude
GOLD Star
thatcabledude
GOLD Star
What an idiot 
- Thread starter
- #39
We all have our moments.What an idiot
- Thread starter
- #40
Definitely a Rodney flush is needed as the oil is no longer oil
. I guess the worst case scenario is Torque converter damage due to the heat? But I doubt it as it’s just viscous friction and not metal to metal friction. No tranny damage to be concerned about as it was just still. I just underestimated how hot it would get in 30 sec. hence it’s a good anecdote for the MUDs.
